The iPhone 5 launch was “and still” big, that it turned out so big that it slowed the growth of Android in the US and the UK, according to Kantar World Panel.

The rest of the EU5 (France, Germany, Italy and Spain) saw just the opposite – Android’s share went up, iOS went down.
It should be noted that iPhone 5 was on sale for only a week in Q3 (even less in some markets) and is yet to launch in China and Brazil, so Q4 is bound to bring big gains for iOS.
Anyway, during this year’s Q3, the market share of iOS in US went up to 35.7%, compared to 21.5% during the same period last year. That’s a massive increase of 14.2 percentage points. Meanwhile Android dropped from 66.4% to 57.5%. Another notable decline is that of BlackBerry, which is now below Microsoft’s OS (which is currently at 2.9%).
In the UK, iOS market share increased by 9.9 percentage points to 18.1%, but Android went up too – from 53.4% to 58.2%. RIM still holds a respectable 8.8% there, while the WP share more than doubled. Symbian practically went extinct in the UK.
iOS shares declined in Germany, France, Italy, Spain and Australia, while Android’s shares increased in these markets. In Germany and Spain in particular, it’s almost complete domination with 77.8% and 82.7% respectively. In Brazil Android went from controlling a fifth of the market to half of it.
In EU5, iOS remained relatively constant, buoyed by its conquests in the UK, while Android went up by 16.2 percentage points. Windows saw decent gains, now controlling about 5% of the market, ahead of the former king, Symbian.
If you want to see all the numbers for all OSes, you can download the PDF from Kantar.